#include<stdio.h>
int main()
{
	int i = 0;
	int cont = 0;

	for (i = 1; i <= 100; i++)
	{
		int j = i;
		{
		start:;
			int k = j % 10;
			j = j / 10;
			if (k == 9)
			{
				cont++;
			}
			if (j != 0)
			{
				goto start;
			}

		}
	}
	printf("%d", cont);
	return 0;
}